12V Battery Dead

[Alemany]

this is 100% incorrect - my Tesla(s) which I've owned since 2013 have had similar problems with 12V issues in spades

I agree this is a screw up by Porsche - but please let's not pretend Tesla is actually any better in this space...I'm a huge Tesla fan (owned 5 Teslas - never more than 2 at once) - and love the cars and what they've done for EV's - but they are far from immune to 12V issues - and right now all the 2017/2018 Model 3's are having big problems with 12V batteries - just read the forums…

Porsche needs to fix this, but Tesla is no better - that's a fact.

Interesting. It is not 100% incorrect, it is my experience. I see yours is different and that is ok. For myself, in 6 years of different Teslas never had an issue with battery, 12V or otherwise. Not trying to start brand mud slinging, just saying this particular issue shouldn't be. Issues with things no one has done, I understand. But this one, specially if you say Tesla had them, why have them?

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[dnanian]

So easy to fix? (a logic to stop checking if battery low, an alert if battery is low, a recharge from main battery system if needed, etc. etc,). I just don't understand.

I think that's because it's probably not that simple...

 

[daveo4EV]

LiON batteries have very little “external” indication they are low on power - the voltage is reasonably stable - you have to implement a dead-reckoning “counter” of power in/out - and just “know” the battery is almost empty - the probably also may be an issue of circumstances where the car will not bring the big battery “online” to charge the 12V - no idea what root cause is - but it’s not the same as a normal ICE starter battery…

Tesla’s had problems in this space, Chevy’s had problems in this space, as have others - Porsche seems to be learning along the way just like everyone else…

 

[KensingtonPark]

Tesla’s had problems in this space, Chevy’s had problems in this space, as have others - Porsche seems to be learning along the way just like everyone else…

Based on my experience, this is absolutely correct. I would add Volvo to the list as well (from my own experience). Seems like they don't share any of this information with each other, either. I suppose because the development for each of the manufacturers is so intensely secret, there is no sharing of any manufacturing challenges that you sometimes get through industry group discussions. So we endure as early adopters...

 

[H@wk]

and so it strikes again - car completely dead on home charger... second time in 3 weeks..... didn’t even open the app in order not to «provoke» the PCM - not that it mattered anyway....

 

[KensingtonPark]

Having been educated by prior EVs, here is what I do:

1. Always actively lock the car. Use the key fob or the door handle to do it. For those with motorized folding side mirrors, I set the option to have the mirrors fold so that I know that I have accomplished it.
2. Store the key in a container lined with aluminum foil. The foil is to trap the key in a Faraday cage so that there is no inadvertent sensing of the key from inside my house. In my case, this is necessary because my office (where I keep my key) is literally above the garage. I have noticed that when I do not store the key in the Faraday cage, sometimes my car will have unlocked on its own. (I know because the mirrors have unfolded.)
3. Do not use the app unless you intend to drive the car soon thereafter. I am not generally inclined to check the app anyway.

Knock on wood, this has helped me avoid dead 12v batteries on my last three plugin vehicles. My operating theory has been that locking the car powers down some aspect of the car's internal system, and any interaction with the vehicle that wakes that system puts the battery at risk. I liken this to early laptops that had bad "sleep" functions: You had to power them down to ensure that they did not drain the batteries. It's just a theory, but I have had good luck with it for a few years now after some bad experiences with dead batteries early on with every one of them.

 

[thenaimis]

FWIW, while I've only had my Taycan for a month, the only time I got any hint of 12V battery discharge was when I'd left it on the charger for an extended period. I'm not driving every day - more like once a week these days in the pandemic. I have to wonder if the 12V battery doesn't get charged if the traction battery is on the charger.

 

[H@wk]

Local dealer have requested all available specs on my wall charger, which is one of the most popular new ones over here (Easee) that presumably works fine with most kinds of EVs. They will then send this to the "importing agency" (I thought they were one and the same, but apparently not). Hopefully they in turn will communicate this to Germany.... Gotta love the continental hierarchical company structures....they love that down there ?

I'm not holding my breath expecting a quick solution to this issue though. So meanwhile I've purchased a start booster. Put the detached plastic cover from the frunk battery compartment on a shelf in the garage along with the fusebox cover which is a PITA to reattach. Also considering a separate charger for the 12volt. Old ICE chargers are incompatible with that I've been told. So all in all about $400 in chargers to be able to be fairly sure that I can get to work every morning.

 

[MartyMeatball]

My Taycan is due in next week. What do you guys think of opening the frunk when it's garaged? This way if the 12V battery dies you don't have to go through the hassle of opening the fuse panel and jumping that to get the frunk open.

 

[NC_Taycan]

My Taycan is due in next week. What do you guys think of opening the frunk when it's garaged? This way if the 12V battery dies you don't have to go through the hassle of opening the fuse panel and jumping that to get the frunk open.

I was doing this for a while after my first and only 12V issue, but I've gotten lax about it. Biggest problem is forgetting it's open. You get in the car, start it up, put it in reverse, then you get the reminder. Curse. Get out. Close the frunk. Get back in. Resume.

 

[Kingske]

My Taycan is due in next week. What do you guys think of opening the frunk when it's garaged? This way if the 12V battery dies you don't have to go through the hassle of opening the fuse panel and jumping that to get the frunk open.

Interesting and original idea.

 

[Gordy]

when does the light go out in the frunk? wouldn't that discharge the battery if left open?

 

[H@wk]

My Taycan is due in next week. What do you guys think of opening the frunk when it's garaged? This way if the 12V battery dies you don't have to go through the hassle of opening the fuse panel and jumping that to get the frunk open.

Great idea! I'm going to start doing this. The car's on a charger anyways - so any light burning in there should be sufficiently charged anyways - until it's not....

 

[Desert05]

Found Dead again this morning after charging to 85%.... had to pull emergency release which is now snapped to release charger...will jump start again tomorrow and flatbed to dealer....(hope its not getting to be like my VIN 23 Fisker which I dumped for a 45% loss after winning the NY
Lemon Law case...but got $0 as Fisker went bankrupt)......

Hopefully the dealer has another trained Taycan Tech who will not give me the same malarkey of closing out of the Porsche Connect App...which I have religiously.... done since getting the car back. Can't wait to hear the explanation this time.

 

[Desert05]

Taycan 4S returned today....new 12V installed. After hearing from all...have deleted Porsche Connect completely from iPhone and will lock car while in my garage also will line the bowl where I keep the keys in foil. Plan on charging tonight 2300-0600 using ChargePoint Flex. Hoping for the best !

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